EV calculator: the expected value of a bet
Expected value (EV) is what a bet wins or loses on average if you placed it many times. Enter your odds and the true chance of winning, as fair odds or as a probability: the EV calculator shows the expected profit in dollars and in percent. Positive EV means the price pays more than the risk is worth.
Positive EV: the price pays more than the risk is worth.
Want to keep a record of your bets and your real profit? Save them in the free Bet Tracker
How to use the calculator
- 1
Enter the stake and your odds
The price the sportsbook offers you, in American or decimal odds.
- 2
Enter the true chance
As fair odds (for example the no-vig price of a sharp book) or as a win probability in percent.
- 3
Read the EV
The expected profit of the bet and the edge in percent. Positive is a valuebet.
Worked example
The Rams are +110 (2.10) at your sportsbook, while the no-vig price of a sharp book is -105, a 51.22% chance. EV of $100 = 0.5122 x $110 - 0.4878 x $100 = +$7.56, an edge of 7.56%. Over hundreds of bets like this, you would expect to earn about $7.56 per $100 staked.
Related calculators
- Kelly criterion calculator The share of your bankroll to bet, sized by the edge.
- No-vig calculator Measure the vig of any market and strip it out to get the fair odds.
- Odds converter American, decimal, fractional odds and implied probability, converted both ways.
- Playthrough calculator How much to wager to unlock a bonus, and what it is really worth.
Frequently asked questions
What is expected value in sports betting?
The average result of a bet over many repetitions: probability of winning times what you win, minus probability of losing times what you lose. Bets with positive EV make money in the long run.
Where do I get the true probability?
The best estimate is the no-vig price of a sharp, high-limit market, which the no-vig calculator computes. Your own model or an estimate works too, but the EV is only as good as the probability you enter.
Does positive EV mean I will win this bet?
No. A +EV bet still loses often; the edge shows up over many bets. That is why stake sizing matters, and the Kelly calculator helps with it.
What is a good EV percentage?
2-5% is a solid edge on main markets; higher values often mean a stale line or an input error. Double-check prices and limits before betting.
How does a bonus bet change the EV?
With a bonus bet the stake is not yours, so losing costs nothing and the EV is the win probability times the net winnings. The bonus bet converter shows how to lock that value in instead.
By the NinjaBet Editorial Team Updated on October 28, 2026
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